Valveless intermittent ram-jet engine



NW0 9 1951 H. R. BOHANON VALVELESS INTERMITTENT RAM-JET ENGINE 2 SI-IEETSSHEET 1 Filed April 8, 1946 Hay R; Bo/mhon N 1951 H. R. BOHANON VALVELESS INTERMITTENT RAM-JET ENGINE 2 SHEETS-Si-EET 2 Filed April 8,. 1946 W n W mv m a a M B R H m Q fl I I I I I I I I I I In m w m L Q m E Q m @d W w k\ w PM. .9 k \g -68:

Patented Nov. 13, 1951 VALVELESS IN TERMITTENT RAM-J ET ENGINE Hoy Rolla Bohanon, Lakewood, Ohio Application April 8, 1946, Serial No. 660,385

(Cl. Gil-35.6)

(Granted under the act of March 3, 1883, as amended April 30, 1928; 370 0. G. 757) 8 Claims.

This invention relates to a jet-propulsion device for airplanes and the like, in which compression of the air is obtained through the forward motion of the airplane, and in which fuel is intermittently injected and exploded and the products of combustion intermittently ejected through discharge nozzles.

In present jet-propulsion devices of this type, spring valves are used in the intake ports to the combustion chamber which are opened during the charging process and closed during explosion. These valves are subject to extremely high stresses and have very short life. It is the purpose of my invention to provide a jet-propulsion system of the type described in which the need for valves is eliminated. Because of this feature, the jetpropulsion system based on this invention has considerably more life than present jet-propulsion systems of the above type.

The object of the present invention is to construct an intermittent jet-propulsion device for aircraft, without valves in the combustion chamber inlet.

A further object is to provide an intermittent combustion cycle in a jet propulsion device by a proper arrangement of ports and an intermittent injection and/or ignition of fuel into the combustion space.

A further object is to provide a, multiple jetpropulsion unit of simple design having a common inlet andair supply space.

A further object is to provide a jet-propulsion system having an air chamber with an air inlet and an air outlet nozzle, a combustiton chamber having an inlet port in said air chamber, a discharge nozzle out to one side of said outlet nozzle, and means for intermittently injecting and igniting a fuel charge.

A further object is to provide a jet-propulsion system of simple design having an air chamber with an air inlet and one or more air outlet nozzles, one or more combustion chambers each having a port in said air chamber face an outlet Fig. 3 shows a modified form of the device;

.and

Figs. 4 to 6 show means for supplying intermittent fuel charges and ignition to the combustion chamber.

With reference to Fig. 1, air chamber 9 is provided at its inlet with an eflicient inlet and diffuser I, and an efficient discharge nozzle 8. Combustion chamber I is provided with an inlet nozzle 2, coaxial with nozzle 8, adapted to draw air from air chamber 9, a discharge nozzle 3, and a tail pipe 4 attached to the end of discharge nozzle 3. Fuel-injection nozzles 5 fed by fuel delivery line I6 are located for injecting fuel into combustion chamber I. A source of ignition, such as spark plug 6 connected to a, source of high tension current by lead I5, is located within the combustion chamber I for igniting the mixture.

The jet-propulsion device operates in the following manner. During the forward motion of the device, air is inducted through the diffuser I to the air chamber 9. The entrance it of diffuser I is designed to provide recovery of part of the velocity head of the entering air into static pressure in the air chamber 9. Part of the air in chamber 9 flows into nozzle 2, and part is dis charged through nozzle 8. While the air is entering combustion chamber I through nozzle 2, fuel is injected through nozzles 5 to provide a combustible mixture. When combustion chamber I is substantially filled with mixture, spark plug '6 is actuated to fire the charge. The highexplosion pressure that ensues forces a jet of gas rearwardly through nozzles 2 and 8 and a second jet is forced rearwardly through nozzle 3 and tail pipe d thereby providing thrust. As the gases leave combustion chamber I, the pressure falls. When the pressure in combustion chamber I falls below the pressure in air chamber 9, a fresh charge is drawn from air chamber 9 into combustion chamber I. Tail pipe 4 aids this discharging process by virtue of the fact that at the end of the discharge process it is filled with a long column of gas moving at a high velocity. The inertia of this column of gas together with a reduction in velocity aids in drawing a fresh charge into combustion chamber I. During the inducting of this fresh charge into combustion chamber I, a fresh charge of fuel is injected and the cycle previously described is repeated.

Fig. 2 shows another jet-propulsion-device embodying my invention. This device is the same as that of Fig. 1 differing only in that two combustion chambers I are located for receiving their air charges from a common air chamber 9. The

fuel-injection nozzles fed by fuel delivery lines II and the spark plugs 8 energized by high tension leads it of these two combustion chambers are timed for alternate operation so that a more steady flow of air at the inlet to diffuser 1 is maintained. It is believed that this arrangement provides an increase in the efficiency of the unit. Items in Fig. 2 that have the same number as items in Fig. 1 also have the same functions as these items and the description of these functions given for Fig. 1 apply to Fig. 2.

Although I have shown nozzles 2 and t as simple nozzles, it is obvious that the various well-known types of nozzles, such as venturi, can also be used.

Fig. 3 shows a jet-propulsion unit similar to that in Fig. l with the addition of a tail pipe l0 attached to the discharge of nozzle 8. The discharge of hot gas through nozzle 2 during the explosion process induces a flow of air thmugh nozzle 8 by virtue of the actuator effect provided by tail pipe III. This action provides some augmentation of the thrust obtained from the jet issuing through nozzle 2.

Fig. 4 shows a mechanism that can be used to provide the intermittent flow of fuel and intermittent spark necessary for operating the combustion chamber. The rotary fuel valve Ii and the spark timing cam 12 are driven by motor I3 at such a speed that they operate with the same frequency as the combustion chamber. The valve l I is supplied by fuel from a source of fuel under in a rearward direction, means for inducting fuel into said combustion chamber during the period when air is entering said combustion chamber, and means for igniting the air-fuel mixture.

2. A valveless air reservoir provided at its entrance with a diffuser facing in the direction of motion and at its exit with a discharge nozzle facing in a rearward direction, two or more intermittently fired combustion chambers of the valveless type each having an entrance nozzle in communication with the air chamber, said entrance nozzles being directed rearwardly and located for coaxial flow with said air chamber discharge nozzles, so that during the period when gases are discharged from the combustion chambers they will proceed through said entrance nozzles and the air chamber discharge nozzles producing propulsive jets, discharge nozzles in communication with each of said combustion chambers, tail pipes attached to the exits of each of said combustion chamber discharge nozzles, said tail pipes being of proper length to be tuned to the rest of the system, said tail pipes also being pointed in a rearward direction, means for inductpressure by the supply line H, and the breaker points I8 are connected in a primary circuit comprising battery l9 and primary coil 20 for energizing the secondary coil 2! which is connected to the spark plug 6 by high tension lead l5.

Other types of valves and spark-timing devices can also be used. The varying combustion chamber pressure can be used to regulate fuel flow, since a reduced combustion chamber pressure would tend to induce high fuel flow as well as high air flow. It is also possible to ignite every charge from the preceding charge, and thus eliminate the need for spark plugs. However, it is believed that control of both fuel and spark will lead to higher efficiency.

Other obvious modifications in form and arrangements of details may be made without departing from the spirit and scope of this invention.

The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

What I claim is:

1. A jet-propulsion device comprising a valveless air chamber provided at its entrance with a diffuser facing in the direction of motion, and a nozzle at its exit facing in a rearward direction, an intermittently fired combustion chamber of the valveless type provided with an inlet nozzle directed rearwardly and adapted to draw air from said air chamber, said inlet nozzle being coaxial with said air chamber discharge nozzle, so that during the period when gases are discharged from the combustion chamber they will proceed through said inlet nozzle and the air chamber discharge nozzle producing a propulsive jet, a discharge nozzle in communication with said combustion chamber, a tail pipe attached to the exit of the discharge nozzle, said tail pipe being of proper length to be tuned to the rest of the system, said tail pipe also being pointed ing fuel into the combustion chambers when air is being inducted into the combustion chamber, and means for igniting the fuel-air mixture, said fuel and ignition means being timed to provide progressively firing of the several combustion chambers.

3. A jet propulsion system of the type described comprising a valveless air chamber having a diffuser at its inlet facing in the direction of motion and a discharge nozzle at its exit facing in a rearward direction, a tail pipe attached to the exit of said nozzle, a valveless intermittently fired combustion chamber having an entrance nozzle directed rearwardly and adapted to draw air from the air chamber, said entrance nozzle being located for coaxial flow with said air chamber discharge nozzle, so that during the period when gases are discharged from the combustion chamber they will proceed through said entrance nozzle and the air chamber discharge nozzle producing a propulsive jet, a discharge nozzle in communication with said combustion chamber, a tail pipe attached to the exit of said combustion chamber nozzle, said tail pipe being of proper length to be tuned to the rest of the system. said tail pipe also being pointed in a rearward direction, means for inducting fuel into the combustion chamber during air induction from said air chamber, and means for igniting the fuel-air mixture.

4. An intermittent combustion device comprising a valveless air chamber having a rearwardly directed discharge nozzle, a valveless combustion chamber, a rearwardly directed inlet nozzle in communication with said combustion chamber and aligned with said air chamber discharge nozzle, a rearwardly directed discharge nozzle in communication with said combustion chamber, a tail pipe attached to the exit of said discharge nozzle, means for intermittent induction of fuel into said combustion chamber during the period when air is inducted from said air chamber, and means for igniting the air-fuel mixture.

5. In a jet propulsion device, a valveless air chamber having a diifuser inlet facing in the direction of motion and a nozzle outlet facing in a rearward direction, a valveless and intermittently fired combustion chamber extending into said air chamber and having a port opening facing rearwardly and axially aligned with said nozzle outlet so that during the period when gases are discharged from the combustion chamber they will proceed through said port opening and the air chamber nozzle outlet producing a propulsive jet, said combustion chamber having a rearwardly directed discharge nozzle to one side of said nozzle outlet, and fuel injection and ignition means in said combustion chamber.

6. In a jet propulsion device, a valveless air chamber having a diffuser inlet facing in the direction of motion and a nozzle outlet facing in a rearward direction, a valveless and intermittently fired combustion chamber extending into said chamber and having a port opening facing rearwardly and axially aligned with said nozzle outlet so that during the period when gases are discharged from the combustion chamber they will proceed through said port opening and the air chamber nozzle outlet producing a propulsive jet, said combustion chamber having a rearwardly directed discharge nozzle to one side of said nozzle outlet, fuel injection and ignition means in said combustion chamber, and a tail pipe connected to the outlet of the discharge nozzle, said tail pipe being of proper length to be tuned to the rest of the system, said tail pipe also being pointed in a rearward direction.

7. In a jet propulsion device, a valveless air chamber having a diffuser inlet facing in the direction of motion and a nozzle outlet facing in a rearward direction, one or more valveless intermittently fired combustion chambers each extending into said air chamber, said nozzle outlet comprising one or more discharge nozzles, there being one discharge nozzle for each combustion chamber, a port opening in each combustion chamber facing rearwardly and aligned with the corresponding discharge nozzle, so that during the period when gases are discharged from the combustion chambers they will proceed through said port openings and the air chamber discharge nozzles producing propulsive jets, and a rearwardly directed discharge nozzle for each of said combustion chambers .parallel to said air chamber discharge nozzles.

8. In a jet propulsion device, a valveless air chamber having a diffuser inlet facing in the direction of motion and a nozzle outlet facing in a rearward direction, one or more valveless intermittenly fired combustion chambers each extending into said air chamber, said nozzle outlet comprising one or more discharge nozzles, there being one discharge nozzle for each combustion chamber, a port opening in each combustion chamber facing rearwardly and aligned with the corresponding discharge nozzle, so that during the period when gases are discharged from the combustion chambers they will proceed through said port openings and the air chamber discharge nozzles producing propulsive jets, a rearwardly directed discharge nozzle for each of said combustion chambers parallel to said air chamber discharge nozzles, and fuel injection and ignition means supplying intermittent combustion in said combustion chambers cyclically to provide a more uniform air supply from said air chamber consecutively to said combustion chambers.

HOY ROLLA BOHANON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Name Date Whittle Aug. 8, 1939 OTHER REFERENCES Number 

